Patents by Inventor Toru Wawaki

Toru Wawaki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for producing aromatic polycarbonate resin
    Patent number: 5929192
    Abstract: A process for producing an aromatic polycarbonate resin by melt polycondensing an aromatic dihydroxy compound and an aromatic carbonic acid diester, wherein a mixture solution comprising the same aromatic monohydroxy compound as a aromatic monohydroxy compound by-produced from a reaction system as a main component and a freezing-point depressant for the aromatic monohydroxy compound, such as a glycol, is used as a scrubbing solution for the recovery of the by-produced aromatic monohydroxy compound by a scrubber type condenser.
    Type: Grant
    Filed: December 11, 1997
    Date of Patent: July 27, 1999
    Assignee: Teijin Limited
    Inventors: Tetsurou Miyauti, Toru Wawaki, Katsushi Sasaki